SAXS Investigation of Core–Shell Microgels with High Scattering Contrast Cores: Access to Structure Factor and Volume Fraction

To explore dense packings of soft colloids, scattering experiments are ideal to access the structure factor. However, for microgels, determination factor is difficult because low contrast polymer network and potential microgel interpenetration deformation that change form contribution. Here, we employ small-angle X-ray (SAXS) study soft, thermoresponsive microgels with poly-N-isopropylacrylamide (PNIPAM) shells gold nanoparticle cores. The cores dominates patterns allows precise volume fraction over a broad range concentrations. At high fractions, find distinct sharp Bragg peaks allowing extraction characterization phases combined UV–vis spectroscopy. unique our core–shell SAXS opens up new ways investigate including in situ studies phase transitions.